An aqueous solution of X on addition of hydrogen peroxide in ice cold conditions gives blue colour to the ethereal layer. Then, X can be

Step-by-step solution

The formation of a blue colour in the ethereal layer upon the addition of hydrogen peroxide ( H₂O₂ ) to an aqueous solution in ice-cold conditions is a characteristic test for the presence of chromium(VI). When H₂O₂ reacts with acidified dichromate or chromate solutions, it forms chromium pentoxide ( CrO₅ ), which is blue in colour. The reaction is as follows: Cr₂O₇²⁻ + 2H⁺ + 4H₂O₂ 2CrO₅ + 5H₂O The CrO₅ species is unstable in aqueous solution and decomposes rapidly, but it is stabilized in ether, where it imparts a